Two-dimensional extremely thin single-crystalline α-Si3N4 microribbons

Two-dimensional extremely thin single-crystalline α-Si3N4 microribbons have been achieved in bulk via a thermal decomposition nitridation. The α-Si3N4 microribbons have small thicknesses of ∼10–20 nm, large widths of ∼10–25 μm and long lengths ranging from several hundred micrometers to the order of millimeters, and have the same growth direction of [101̄0] crystallographic orientation and are enclosed by ±(0001) and ±(21̄1̄0) facets. Room temperature cathodoluminescence from individual ribbons shows one intensive UV emission peak at ∼305 nm, and two weak and broad emission peaks at ∼540 and ∼735 nm, respectively. The form of α-Si3N4 is expected not only to possess many interesting mechanical properties, but also to have different optical properties.